/*
Copyright 2022 Huawei Cloud Computing Technologies Co., Ltd.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package rand

import (
	"crypto/rand"
	"encoding/binary"
	rand2 "math/rand"
)

const (
	rngMask = (1 << 63) - 1
)

/* #nosec */
var defaultRand = rand2.New(&Source{})

type Source struct {
}

func (s Source) Int63() int64 {
	var i uint64
	err := binary.Read(rand.Reader, binary.LittleEndian, &i)
	if err != nil {
		return 0
	}
	return int64(i & rngMask)
}

func (s Source) Seed(int64) {

}

func Int63() int64 {
	return defaultRand.Int63()
}

func Intn(n int) int {
	return defaultRand.Intn(n)
}

func Int63n(n int64) int64 {
	return defaultRand.Int63n(n)
}

func Float64() float64 {
	return defaultRand.Float64()
}

func Int31n(n int32) int32 {
	return defaultRand.Int31n(n)
}
